that was easy Lisa carr averaged a speed of 55 miles per hour
she may not have been traveling at a constant speed of 55 mi/hr. She undoubtedly, was stopped at some instant in time (perhaps for a bathroom break or for lunch)and she probably was going 65 mi/hr. at other instants in time. Yet, she averaged a speed of 55 miles per hour. The above formul represents a shortcut method of determinning the average speed of an object